High-speed printing apparatus



y 19, 1964 c. R. M. MARTIN 3,133,497

HIGH-SPEED PRINTING APPARATUS Filed Dec. 24, 1962 3 Sheets-Sheet 1 y 1964 c. R; M. MARTIN: 3,133,497

HIGH-SEEED PRINTING APPARATUS Filed Dec. 24,. 1962 3 Sheets-Sheet; 21

lmlllllll FIG. 2

FIG.3

y 19, 1954 c. R. M. MARTIN 3,133,497

HIGH-SPEED PRINTING APPARATUS Filed Dec. 24, 1962 3 Sheets-Sheet 3 United States Patent 3,133,497 MESH-SPEED PRHNTING APPARATU Claude Raymond Marie Martin, Paris, France, assignmto Compagnie des Machines Bull (Socit Anonyme), Paris, France Filed Dec. 24, 1962, Ser. No. 246,775 Claims priority, application France Jan. 9, 1962 4 Claims. ((31. 101-93) This invention relates to printing apparatus.

For the purpose of increasing the speed of operation of a printing apparatus in which the type support is stopped for the striking action, it is necessary to shorten the times required for the selection and striking of each character. In order to achieve this, efforts have been made to minimize the masses involved in the selecting and striking movements, and printing apparatus have been proposed in which the type are supported by flexible belts and in which the striking of a character is accompanied by a momentary local deformation of the belt on which it is mounted.

In such apparatus, if the members for driving and guiding the belt are disregarded, only the belt bearing the character which is to be printed is set in movement in the course of a character-selecting operation and only one portion of this belt is deformed and displaced in the course of the operation of printing the selected character.

In some of these known apparatus, the belt is closed and mounted in the manner of a transmission belt between two pulleys. Consequently, the belt is subjected, at the instant of the striking, to a relatively high force resulting from a fairly considerable elastic deformation, and the displacement of the character struck is limited. This disadvantage is not obviated if one of the pulleys is mounted on springs, because the force of inertia of the pulley in the course of the rapid movement of the character struck remains considerable.

In another of these known apparatus, the belt is not closed, but is tensioned by a. spring at the end opposite to that at which the driving force for the selection is applied. With such an arrangement, the aforesaid disadvantage can be lessened, because the resilient force exerted by the spring may be made sufficiently small to permit placement of the belt in the other direction takes place under the actionof the motor, which'must not only overcome the forces of inertia, but must also retension the spring.

In these known apparatus, pulleys are so disposed as to guide the type belt. These pulleys are rotated by the belt when the latter moves in the course of the operation of selecting a character. This correspondingly increases the forces of inertia opposing the movement carried out by the belt during this character-selecting operation.

in accordance with the present invention there is provided printing apparatus comprising a type carrier in the form of a flexible open belt or strip having at least two longitudinal slits or slots which separate two lateral portions of the belt from a central portion of the belt, said central portion carrying printing types over a part of its length, said apparatus further comprising two lateral slideways for guiding. the edges of the belt, a hammer located on one side of the belt, and means for driving the belt along the slideways so as to position a selected type opposite the hammer.

3,133,497. Patented May 19, 1964 The apparatus may also comprise one or more of the following features:

The type or characters in relief borne by the central portion of the belt may be so disposed as to form a row parallel to the longitudinal axis of the belt;

The type or characters in relief borne by the central portion of the belt may be so disposed as to form a number of rows parallel to the longitudinal axis of the belt, each row being separated from the neighboring row by a longitudinal slot of the same length as the slots separating the said central portion from the said lateral portions of the belt, there being a row-selecting device for displacing the slide-ways in relation to the striking device in a direction perpendicular to the longitudinal axis of the belt so as to render possible the striking of a type or character of any one row of characters;

The driving device may comprise a motor having a driving shaft and a driving dog, of which one end is connected to the driving shaft and of which the other end is engaged in an aperture in the type, belt, that portion of the slide-ways which guides the portion of the belt having the said apertures being curved about the axis of the driving shaft, so that the said portion of the belt forms a cylindrical surface of revolution, of which the axis of revolution is identical with that of the driving shaft.

For a better understanding of the invention and to show how it may be carried into elfect, the same will now be described, by way of example, with reference to the accompanying drawings, inwhich:

FIGURE 1 is a perspective view of printing apparatus comprising a type belt according to one embodiment of the invention,

FIGURE 2 is a side View of the type belt of the apparatus,

FIGURE 3 is a sectional view of the apparatus taken along lines 3--3 of FIGURE 1, some of the parts having been omitted to simplify the drawing,

FIGURE 4 is a fragmentary sectional view taken along lines 4-4 on FIG. 3, drawn to a larger scale, and

FIGURE 5 is a fragmentary View in perspective of printing apparatus comprising a type belt according to a modified embodiment of the invention.

In the constructional form illustrated in FIGURES 1 to 4, the printing apparatus comprises a flexible belt 10 (FIGURE 2) having four internal longitudinal slots 111, 112, 113 and 114. The slots 111 and 114 each separate a lateral portion, i.e., 191 and 102 respectively, from the central portion of the belt. The other slots 112 and 113 divide the central portion of the belt into three strips 103, 104 and 1495, each of which bears a series of types or character-sin relief 20 disposed in a row parallel to the longitudinal axis of the belt. The longitudinal slots are a little longer than the rows of characters and extend beyond them at the ends.

The belt 10 is guided as indicated in FIGURE 1 in two lateral slide-ways 31 and 32. Each of the slideways is curved at one of its ends in a plane perpendicular to the surface of the belt in such manner that the end of the belt engaged in the curved ends of the slide-ways forms a cylindrical surface of revolution.

With such an arrangement, it is possible to displace the belt in either direction by pulling it or pushing it at one of its ends by means of a driving device40 which comprises a driving dog 41 extending through an aperture 115 in the belt and a driving shaft 42 controlling the movement of the driving dog 41, the axis of the driving shaft being identical with the axis of revolution :of the cylindri cal surface formed by the end of the belt engaged in the curved ends of the slide-ways.

The shaft 42 may be driven in either direction-by an electromagnetic step-by-step motor so as to take up any one of n equidistant positions comprised within an angle of rotation equal to the angle in which is inscribed the curved portion of the slide-ways, n being the number of characters in each row.

The driving dog 41 is pivotally connected at 43 to the driving shaft 42 so as to pivot freely about an axis perpendicular to the said shaft, whereby it is possible to displace the assembly comprising the slideways and the belt in a direction parallel to the shaft in order to select one of the rows of characters for striking.

A device 60 is provided for selecting the rows of characters. It comprises guide rails 61 and 62 parallel to the axis of the driving shaft. These rails are fixed to the slide-ways 31 and 32 and are guided in the frame (not shown) of the printing apparatus, so as to permit the displacement of the belt in a direction perpendicular to its longitudinal axis, while the motor remains fixed. By such a displacement of the belt, one of the rows of characters can be selected.

The character row selection may be effected by means of a rack-and-pinion mechanism as diagrammatically illustrated in FIGURE 1. It will be understood that the selecting device 60 just described is not the only one suitable for the purpose. Such a device may be designed in various ways, for example in such manner that the selection is effected by a rotation of the belt.

The striking device 56 (FIGURES l, 3 and 4) is fixed to the frame (not shown) of the printing apparatus. It comprises essentially an electromagnetic striking motor 51 and a hammer 52. FIGURES 1 and 3 illustrate the striking device in the inoperative position. FIGURE 4 illustrates the striking device at the instant when the hammer projected by the armature of the striking motor applies a character 201 and the inking ribbon 55 against the paper 56. The character 201 is then displaced by the hammer out of the plane of the open belt or strip and this brings about a deformation of the tape on which it is located. This deformation is limited to that portion of the strip which does not bear against the plates 57. The plates 57 (FIGURES 3, 4), solidwith slide-ways 31, 32, are located at the level of central slots 112, 113 and are interrupted on a suitable length on either side of the striking hammer 52. If that portion of the strip which is thus deformed is sufficiently short, the curvature imparted thereto may be sufficiently accentuated to render possible printing on plane surfaces. The deformation of the strip causes the two ends of the belt to move one towards the other, so that the other strips and the lateral portions must become curved or assume a sinuous form. In order to render possible this deformation of the lateral portions of the belt, sufficient clearance is provided in a portion of the slideways, as illustrated in FIGURE 4. The clearance provided in the curved portions of the slide-ways, on the other hand, is the smallest possible for avoiding inaccuracy in the positioning of the characters.

The character displaced at the instant of the striking simply performs the function of an interposed member, and does not affect by its mass the efliciency of the striking device. The mass of each character may therefore be as small as is permitted by manufacturing methods.

In a modified embodiment of the invention as illustrated in FIGURE 5, the printing apparatus comprises rectilinear slide-ways 31' and 32 and a linear motor 45 driving the character-supporting belt 10 through a nonarticulated driving dog 41 extending through an aperture 115 in the belt. This aperture 115 is of elongated form in a direction perpendicular to the longitudinal axis of the belt, so that the belt can be displaced perpendicularly to its longitudinal axis for the selection of the rows of characters.

The simplicity in the construction of the connecting members disposed between the motor and the charactersupporting belt will be apparent from the foregoing description. Since the said belt has only one point of attachment to the driving mechanism, it is readily detachable.

As is also apparent from the foregoing description, the total mass of the character-supporting belt of an apparatus according to the described embodiments may be very small. In addition it will be noted that the mass of the members by which the mechanical connection is established between the motor and the belt is small in relation to the total mass of the character-supporting belt. This lightness of the movable elements of the apparatus renders possible very rapid displacements of the belt between any positions, and consequently rapid selection of any character in any row of characters. It is owing to this possibility of rapid selection of a character in a number of rows of characters that the apparatus may have considerably higher performances than systems in which all the characters are disposed in a single row.

As has been indicated in the description, a small clearance is provided in the curved portions of the slide-ways, while a larger clearance is provided in the slide-ways in the neighborhood of the striking device in order to allow sufficient space for the sinuous forms assumed by the lateral portions of the belt during the striking of a character. This larger amount of clearance need not be constant along the slide-ways in'those portions of the latter which are fairly remote from the striking device, and the connection between the portions of the slide-ways which comprise different clearances may be continuous or discontinuous.

In the apparatus according to the described embodiments, the belt is formed of polyethylene terephthalate and the slide-ways are coated with polytetrafiuoroethylene in order to limit to a small value the frictional forces exerted on the belt in the course of its displacement.

It is also to be noted that the friction of the belt in the slide-ways produces a desirable damping effect if it is well adjusted.

I claim:

1. In a printing apparatus having a striking hammer located in front of a paper sheet on the same side as a printing line to be printed, a combination comprising an elongated type-carrier strip made of a thin flexible material, this strip being fitted with at least one central portion bearing a series of character types which can be printed, and separated from two lateral portions by at least two slots which extend on a length substantially equal to the length of said series of types, guiding means for locating said strip between the paper sheet and said striking hammer and for permitting the displacement of said strip parallel to the printing line by guiding said lateral portions, and driving means coupled to one end of said strip for displacing the latter parallel to said printing line in either sense in order to bring a selected character type in a printing position in front of said striking hammer.

2. The combination claimed in claim 1, in which said guiding means comprise two grooved slide ways which extend along with said one end of said type-carrier strip and which are curved in form of a cylindrical portion tangential to the plane of said strip, and said driving means comprising a shaft located on the axis of said cylindrical portion and being fitted with a radial dog having a pin-and-slot connection to said one end of said strip.

3. In a printing apparatus having a striking hammer located in front of a paper sheet on the same side as a printing line to be printed, a combination comprising an elongated type-carrier strip made of a thin flexible material, this strip being fitted with at least two central portions bearing each a series of character types which can be printed, said central portions being separated from each other and from two lateral portions by slots which extend on a length greater than that of said series of types, guiding means for locating said strip between the paper sheet and said striking hammer and for permitting the displacement of said strip by guiding said lateral portions, a displacing device coupled to said guiding means for locating said guiding means together with said type-carrier strip so that one of said central portions lies at the level of said striking hammer, and driving means coupled to one end of said strip for displacing the latter parallel to said printing line in either sense in order to bring a selected character type at a printing position coincident to the position of said striking hammer.

4. The combination claimed in claim 3, in which said guiding means comprise two grooved slide-ways which extend along with said one end of said type-carrier strip and which are curved to form a cylindrical portion tangential to the plane of said strip, and said driving means comprising a shaft located on the axis of said cylindrical portion and being fitted with an oscillating radial dog having a pin-and-slot connection to said one end of said strip.

References Cited in the file of this patent UNITED STATES PATENTS 

1. IN A PRINTING APPARATUS HAVING A STRIKING HAMMER LOCATED IN FRONT OF A PAPER SHEET ON THE SAME SIDE AS A PRINTING LINE TO BE PRINTED, A COMBINATION COMPRISING AN ELONGATED TYPE-CARRIER STRIP MADE OF A THIN FLEXIBLE MATERIAL, THIS STRIP BEING FITTED WITH AT LEAST ONE CENTRAL PORTION BEARING A SERIES OF CHARACTER TYPES WHICH CAN BE PRINTED, AND SEPARATED FROM TWO LATERAL PORTIONS BY AT LEAST TWO SLOTS WHICH EXTEND ON A LENGTH SUBSTANTIALLY EQUAL TO THE LENGTH OF SAID SERIES OF TYPES, GUIDING MEANS FOR LOCATING SAID STRIP BETWEEN THE PAPER SHEET AND SAID STRIKING HAMMER AND FOR PERMITTING THE DISPLACEMENT OF SAID STRIP PARALLEL TO THE PRINTING LINE BY GUIDING SAID LATERAL PORTIONS, AND DRIVING MEANS COUPLED TO ONE END OF SAID STRIP FOR DISPLACING THE LATTER PARALLEL TO SAID PRINTING LINE IN EITHER SENSE IN ORDER TO BRING A SELECTED CHARACTER TYPE IN A PRINTING POSITION IN FRONT OF SAID STRIKING HAMMER. 